Automatic musical instrument.



H. C. DREXELIUS.

AUTOMATIC MUSICAL INSTRUMENT.

APPLICATION FILED JUNE 16. I914- RENEWED FEB. 14.1918.

1,282,393. Patented Oct. 22, 1918.

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Patented Oct. 22, 1918.

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H. C. DREXELIUS.

AUTOMATIC MUSICAL INSTRUMENT.

APPLICATION FILED JUNE 16, I914. RENEWED FEB. 14.!9l8.

Patented Oct. 22, 1918.

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, I INVENT R hY ATTURNEYj.

H. C. DREXELIUS.

AUTOMATIC MUSICAL INSTRUMENT.

APPLICATION FlLED JUNE I6, I914- RENEWED FEB. 14, I9I8.

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INVEN-TDR ATTUFINEYEI.

UNITED sTATEs PATENT OFFICE.

HENRY COREY DREXELIUS, OF NORTH TONAWANDA, NEW YORK, ASSIGNOR TO THE RUDOLPH WURLITZER MANUFACTURING COMPANY, OF NORTH TONAWANDA, NEW

YORK, A CORPORATION OF NEW YORK.

AUTOMATIC MUSICAL INSTRUMENT.

Specification of Letters Patent.

Patented Oct. 22, 1918.

Anpli ation filed June 16, 1914, Serial No. 845,350. Renewed February l' l, 1918. Serial No. 217,255.

To all whom it may concern:

Be it known that I, HENRY COREY DnnxnLIUs, a citizen of the United States, residing at North Tonawanda, in the county of Niagara and State of New York, have invented new and useful Improvements in Automatic Musical Instruments, of which the following is a specification.

This invention relates to keyed musical instruments, such as pianos, which are adapted to be played either automatically or manually, and more particularly to an instrument of this kind in which a plurality of trackers and music sheets are employed.

The object of my invention is to provide such instruments with reliable means for permitting the selection of the pieces on the music rolls without interfering with the continuous playing of the instrument, thus rendering the same especially desirable for moving picture theaters and similar places of amusement, inasmuch as it permits the music to be suited to any style of film.

In the accompanying drawings: Figure 1 is a front elevation of an automatic piano embodying the invention with the front wall of the case removed, the piano action and the strings being omitted for clearness. Figs. 2 and 3 are diagrammatic views showing the roll driving mechanisms of the two trackers in different positions. Fig. 4c is an enlarged front elevation of the roll driving mechanism of one of the trackers. Fig. 5 is an end elevation of the same. Fig. 6 is an enlarged side view of the controlling pneumatics. Fig. 7 is a horizontal longitudinal section of the cut-off board on line 7--7, Fig. 2. Fig. 8 is a vertical longitudinal section of the cut-off board on line 8-8, Fig. 2. I

Similar characters of reference indicate corresponding parts throughout the several views.

'1 indicates the main Wind chest containing a pneumatic playing action of any suitable construction, and 2, Figs. 2 and 3, indicates one of the lcustomary striker ,or playing pneumatics. The wind chest is connected with the customary pump or main suction bellows 3 operated by an electric or other suitable motor 1. Interposed between the main wind chest and the bellows 3 is a valve box or case 5 containing a cut-off valve 6. A suction trunk 7 connects this case with said bellows.

The instrument contains tWo trackers or tracker frames and associated roll-driving and controlling mechanisms which as a whole are designated by. the reference letters A and B, respectively, and for brevity are hereinafter referred to as trackers A and B. They are identical in construction and a description of one will therefore apply to both.

8 indicates the tracker board, 9 the music roll, 10 the take-up roll and 11 the music sheet. The right hand end of the take-up roll-spindle is engaged with the usual clutch member or. head 12 secured to the take-up shaft 13, while the rewind roll-spindle is engaged by the clutch member 14 secured to the rewind shaft 15, which shafts are journaled in the cheeks 16 of the tracker boxes or frames The rewind shaft carries a spur gear 17 engaging an idler 18. ,Mounted on the take-up roll shaft 13 is a spur gear 19.

20 indicates a main driving shaft common to both trackers and extending horizontally through one of the tracker boxes and journaled therein. Fixed to this shaft 20 adjacent to each tracker box is a spur gear 21. Pivoted upon the shaft 20 is a verticallymovable rock arm 22 carrying three transmission gears 23, 2 1, and 25, which are secured to a spindle 26 journaled in said arm. The gear 23 is in constant mesh with the gear 21 on the main drive shaft 20 which is constantly rotated during the operation of the instrument. When the rock arm 22 is raised, the gear 2 1 meshes with the rewind idler 18, while when said arm is lowered, the gear 25 meshes with the take-up gear 19. The transmission gears 24: and 25 are arranged between the spur gears 18 and 19,

and the constant rotation of said transmission gears causes the music sheet to be taken up or rewound, according as said rock arm is moved down or up.

The main drive shaft 20 is preferably driven from an upright shaft 27 by friction disks 28 and 29, the shaft of the friction disk 29 being connected with the drive shaft 20 by a universal connecting shaft 30. This upright shaft may be driven from the motor 4 by any suitable means, that shown in the drawings including a horizontal shaft .1 and worm gearing 32.

The shifting of the rock arm 22 is preferably effected by the following means:

33 and 3% indicate bellows or neumatics located adjacent to the roll-driving mechanism and serving respectively to shift the rock arm 22 into rewind and take-up position. This arm is connected by a link 35. with a strap or bar 36, connected at its ends to the upper movable board of the upper pneumatic 33 and the lower movable board of the lower pneumatic 34:, as clearly shown in Fig. 6. These pneumatics are alternately inflated and deflated by any suitable or well known means. Those shown in the drawings co1nprise a valve block 37 preferably located on the underside of the key board and a cooperating slide'valve 38. This block is provided with a suction port 39 and a pair of combined suction and flushing ports 40 and ll, all of which ports terminate at the lower face of said block. The valve 38 contains a ort d2 constructed to alternately connect t e block-ports 40 and 41 with the suction port 39. The latter is in constant communication with a valve chamber 43 of the cut-off box 5, as shown in Figs. 2 and 3. This valve chamber is connected by ports A l with a suction chamber 45 in turn connected by the trunk 7 with the main suction bellows 3, and said valve is connected by ports 46 with a flushing chamber i7 communicating with the atmosphere by an opening $8. The ports l4 and 46 are controlled by a duplex valve 6 actuated by a pouch or diaphragm 4-9 of ordinary construction. Normally the flushing ports 46 are closed and the suction ports ii are open, as shown.

The slide valve 37 is operated by a pair of oppositely-acting pneumatics 50 and 51, the movable boards of which are arranged to engage opposite ends of the valve. These pneumatics are individually connected-with an auxiliary wind chest 52 preferably arranged on the underside of the key table and having its suction chamber 53 connected with the valve chamber 43 of the cut off valve by a trunk 5%. The pneumatic 50 is connected by a conduit 55 with a valve chamber 56 in the auxiliary chest 52, which chamber is connected with a flushing chamber 57 and the suction chamber 53 by ports, which are controlled by a duplex valve 58 of ordinary construction. This valve is controlled by a primary pneumatic 59 to which leads a conduit 60 connected with a corresponding duct (31 of tracker A. The pneumatic is connected with a wind chest chamber 62 similar to the chamber 56 and is controlled by a valve 63 andpneumatic 645, from which'latter leads a conduit 65- connected with a corresponding duct 61 of the tracker B.

The playing or take-up bellows 33 of ra k A .5 QQ IIIectedwith th P9 40 of the valve block 37 by a conduit 66, while the playing bellows 33 of the tracker B is connected with the port 41 of said block by a conduit 67, and these bellows are alternately inflated and deflated by the shifting of the valve 38 in an obvious manner.

The rewind bellows 34: of tracker A is connected by a conduit 68 with a valve chamber 69 of the auxiliary chest 52, which chamber is connected by ports 70 with the flushing chamber 57 and by ports 71 with a combined suction and flushing chamber 72, which is independent of the main suction chamber 53. These ports are controlled by a duplex valve 73. the heads of which are arranged on the outer side of the chamber 69. This valve is in turn controlled by a diaphragm 74, as hereinafter described. The rewind bellows 34 of tracker B is connected with a similar chamber 75 by a duct 76 and a valve 77 similar to. the valve 73,the latter being actu ated by a pneumatic 78.

The suction and flushingchamber 72 is' connected with the port. 41 of'the valve block 37 by the conduit's 79 and 67 while the chamber 80 is connected with the. port 40 of said valve block by conduits 81 and 66. Thus the. rewind bellows areialternately inflated and deflated by the shifting of the slide valve 38 of said block.

By this construction and arrangement of the controlling mechanism, the playing pneumatic 33. of tracker A is collapsed when the rewind pneumatic 34 of tracker B. is inflated, thus driving the music. sheet of tracker A and rewinding the sheet oftracker B. The same statement applies to the playing bellows 33 of tracker B and the rewind bellows 34 of tracker A.

The actuation of these sets of playin and rewind bellows is automatically e ected after the p-laying'of each roll by perforations 82 located near the ends of the music sheets 11 and which register with the ducts 61 of the tracker boards in a well known manner.- As the rewind operation of the music sheet is more rapid than the winding or playing operation, means are provided for stopping the rewind mechanism of the played roll while the take-up mechanism of the playing roll continues. This stopping mechanism operates, to shift the transmission gears 23, 2d and 25. to a neutral or intermediate position in which they drive neither the music roll nor the take-up. roll. It is preferably constructed as follows:

83 indicates. a stopping pneumatic or bellows located above the playing b lows 33 and serving when collapsed to move and hold the rock arm 22 in neutral or intermediate position, each of the, trackers A and B havingsucha stop in}; bellows. These bellows are inclividualllyoonnectediby conduits 84 and with chambers 85 and 86 to the auxiliary wind chest 52 and are controlled by valves 87 and 88 similar to the chambers 56 and valves 58. The valve 87 is controlled by a primary pneumatic 89 from which leads a conduit 90 controlled by a flushing valve 91. of tracker A. The valve 88 is controlled by a primary pneumatic 92 from which a conduit 93 leads to a flushing valve 91 of tracker B. Each of these flushing valves preferably consists of a spring-pressed pallet which normally closes a port 94 in a block 95.

96 indicates fingers which coiiperate with the take-up rolls 10, respectively, and control the flushing valves 91 of the stopping bellows 83. Each of these fingers is pivoted at its lower end to a vertically movable rock arm 97 secured to a horizontal shaft 98, .arranged parallel with the take-up roll and on the front side thereof, and is supported in the adjacent tracker box. A trip finger 99 extending rearwardly from the shaft 98 engages under the flushing valve 91. Secured to the shaft 98 is an additional rock arm 100 which is connected with the rock arm 22 by a link 101.

As seen in Fig. 5, the finger 96 bears against the convolutions of the music sheet opposite a transverse groove or recess 102 in the periphery of the take-up roll, the finger bearing constantly against the music sheet by its own weight and held in its uppermost position by a spring 103. This recess has an abrupt rear end 104: referring to the direction of travel of the take-up roll during the rewinding of the music sheet. So long as the recess remains covered by the music sheet during the rewinding operation, the finger is held in a retracted position, as shown in Fig. 5. cess is uncovered by the complete unwinding of the music sheet, the finger drops into the recess and its upper end is brought into the path of the abrupt end of the recess, thereby depressing the finger and causing it to rock the shaft 98 in the proper direction to lift and open the valve 91, thereby flushing the primary pneumatic 89 or 92 as the case may be and collapsing the stop bellows 83 to lower the transmission gears 23, 241 and 25 into neutral position. The connection 101 between the rock arm 22 and the shaft 98 is preferably employed to assist the stopping bellows 83 in disconnecting the transmission gear 24 from the idler 18.

As soon however as the re-- fixed board 107 of the adjacent playing bellows 33 and at its lower end to the lower movable board of the rewind bellows 34, whereby the weight of the arm 22 and the transmission gears 23, 24: and 25 is transmitted to said spring through the link 35 and the strap 36. It should be noted however that this spring is light enough to allow the playing bellows 33 to overcome its resistance. The movable board of the stopping bellows carries a suitable adjustable stop 108 for limiting its closing movement when the arm 22 is lowered to its neutral position.

To e-fl'ect the above-mentioned deflation of the rewind bellows 34: simultaneously with the inflation of the stopping bellows 83, the primary pneumatics 74: and 78 of the rewind bellows are connected by conduits 109 and 110 with the conduits 93 and 90 which latter lead to the pallet-valves 91. When one of these valves 91 is opened the corresponding valve 73 is raised, thereby disconnecting the rewind bellows 34 from the suction chamber 72 and connecting it with the flushing chamber and causing its inflation.

During the rewind of each music sheet, the corresponding tracker is cut off from the main wind chest by any suitable means, but I prefer to employ the mechanism shown in the drawings which is constructed as follows:

111 indicates a cut-off board or chest preferably arranged on top of the main wind chest 1 and containing a pair of pouch or valve chambers 112 and 113. One of these chambers, say the chamber 112 is connected by a conduit 114 and the conduit 66 with the port 40 of the block 37, while the chamber 113 is connected by a conduit 115 and the conduit 67 with the block-port 11, whereby each of said chambers is alternately exhausted and flushed by the shifting of the slide valve 38. Arranged in the cut-off chest 111 adjacent to the pouch chamber 112 are a plurality of channels 116 respectively connected with the ducts 61 of tracker A by conduits 117. Arranged adjacent to the other pouch chamber 113 is a similar set of channels 118 to which are connected conduits 119 forming a continuation of the respective tracker ducts of tracker B. The pair or set of channels 116 and 118 corresponding to like note-ducts of the two tracker boards 8 bothcommunicate witha common channel 120 leading to the primary pneumatic 1.21 which controls the valve 122 of the corre sponding striker pneumatic 2. Each of the channels 11.6 is divided or interrupted'by a partition123 and provided on opposite sides of said partition with ports 124 which are covered by a pouchor flexible diaphragm 125 secured at its edge to the top of the up per pouch chamber112. These ports extend through the bottoms of the channels 116 and the corresponding pouch 125 forms a valve which, when elevated against the lower edge of the partition 123, closes the ports 124 and cuts 011' communication between the corresponding primary pneumatic 121 and the corresponding duct of the board 8 of tracker A; while when said pouch valve is lowered, it opens said ports and forms a by-pass between them, thereby connecting said primary pneumatic with said tracker board duct. It will be understood that there is such a pouch valve for each channel 116.

Each of the channels 118 has a similar partition 126 and a pair of ports 127 controlled by a pouch valve 128.

From the foregoing it will be seen that when the playing bellows 33 of tracker A is deflated by the shifting of the slide valve 38, the pouch chamber 112 of the corresponding tracker is at the same time exhausted, drawing the pouch valves 125 away from the ports 124, and allowing communication between the tracker ducts 116 of tracker A and the primary pneumatics 121 of the main wind chest. Simultaneously with this action the pouch chamber 113 is connected to the atmosphere by the uncovering of the port 41 in the block 37, depressing or closing the pouch valves 128 over the ports 127 and thereby cutting off the tracker ducts of the tracker B from the main wind chest.

When the slide valve 38 is shifted to the opposite position, the pouch-valves 125 corresponding to tracker B are opened and the pouch-valves 128 corresponding to tracker A are closed, cutting off the tracker A from the main wind chest.

It may be desirable at times while one music sheet is being played to select some particular piece of the idle music sheet and move it into position ready to be played when desired. This is preferably accomplished by the following mechanism:

The take-up shaft 13 is provided with an auxiliary driving spur gear 129 which engages with an idler 130 journaled on a vertically movable rock arm 131 pivoted on the shaft 15. The idler 130 in turn is adapted to engage with the spur gear 21. The gear 129 is of larger diameter than the spur gear 25 used in driving the take-up roll at playing speed, thus saving time in selecting the desired composition.

The shifting of the rock arm 131 is preferably effected by the following means:

132 indicates a bellows or pneumatic which serves when collapsed to shift the rock arm 131 into operative or selecting position and which is connected with said arm by a link 133. A spiral spring 134 serves to draw this rock arm 131 into inoperative position when the bellows 132 is inflated. The two bellows 132 of the trackers A and B are individually connected by conduits 135 and 136 with separate valve chambers 137 and 138 in the auxiliary wind chest 52 and these bellows are controlled by valves 139 and 140, respectively, and corresponding primary pneumatics 141 and 142 arranged in suction chambers 143 and 144. The rimary pneumatic 141 is connected by a. con uit 145 with a port 146 arranged in a valve-bar or case 147 and controlled bya slide valve 148 operated by a hand lever 149. The pneumatic 142 is connected by a conduit 150 with a port 151 in the case 147 and controlled by a similar valve 152 actuated by a hand lever 153. The uncovering of either of the ports 146 and 151 by the movement of the lever'149 or 153 causes the collapse of the corresponding selecting bellows 132 and the shifting of the selecting mechanism into operative position.

The suction chambers 143 and 144 are connected respectively by conduits 154 and 155 with auxiliary valve chambers 157 and 156 in the auxiliary chest 52. The chambers are alternately connected with the flushing chamber 57 and auxiliary suction chambers 158 and 159 by valves 160 and 161 similar to the valve 77. The suction chamber 156 is connected with the port 40 of the valveblock 37 by a conduit 162 and the conduit 66. The suction chamber 159 is connected with the port- 41 of said block b a conduit 163 and the conduit 67, where y said suction chambers 158and 129 andthe suction chambers 143 and 144 connected therewith are alternately exhausted and flushed by the shifting of the slide valve 38.

Under ordinary conditions, the roll drivingmechanism is automatically thrown into rewind position after playing the complete roll and continues to rewind until automati cally stopped. The selecting is done manually. and as the operator is apt to do so during the rewinding operation, means must be provided to shift the transmission gears 23, 24 and 25 into neutral or inoperative -po sition before the selecting mechanism is thrown into operative position, otherwise the rewind mechanism will interfere with the selecting mechanism. This shifting action is accomplished preferably by the following means:

164 and 165 indicate auxiliary ports arranged in the bar 147 adjacent tothe ports 146 and 151, respectively, and controlled by the valve blocks 148 and 152. These ports 164 and 165 are connected by conduits 166 and 167 with the primary neumatics 89 and 92 which control the stopping bellows 83; and by conduits 168 and 169 with the primary Pneumatics 74 and 78 which control the rewind bellows 34. The hand levers 149 and 153 are movable into three operative'positions, viz: rewind, stop and select, and are set in rewind position, as shown, when the instrument is to pla. continuously without the operator ma g selec tions. When either of these levers is moved to select position for selecting a piece, it first passes through stop position and opens the port 164 or 165, raising the primary pneumatic 78 or 74, and exhausting the corresponding rewind bellows, and also raising the primary pneumatic 89 or 92, and deflating the corresponding stop bellows 83, thereby shifting the transmission gears 23 25 into inoperative position. When either of said levers reaches select position, the port 146 or 151 is opened and the primary pneumatic 141 or 142 is raised, causing the corresponding selecting bellows tocollapse and throwing the selecting gear 130 into operative position.

As before stated, after one music sheet has finished playing, a perforation at the end thereof causes the other music sheet to start playing. As the operator might be in the act of selecting a piece on the idle music sheet at the time this change occurs, the suction supply to each selecting bellows 132 is arranged to be cut ofi an instant before the other playing bellows 33 comes into operation to allow the spring 134 to withdraw the selecting gear 130 from the drive gear 21 and prevent said gear 130 from interfering with the operation of the playing gear 25. The bellows-conduits are connected so that the suction supply to the playing bellows 33 of tracker A is through the same conduit as that of the selecting bellows 132 of tracker B, and the suction supply of the playing bellows 33 of tracker B is through the same conduit as that of the selecting bellows 32 of tracker A, as can readily be seen in Figs. 2 and 3, by noting that conduit 162 is connected with conduit 66; and conduit 163 is connected with conduit 67. This arrangement makes it impossible for the selecting and playing gears 130 and 25 of the same tracker to come into operation at the same time.

In selecting a piece near the end of the music sheet, the latter is liable to run off the music spool, unless means are provided for automatically disconnecting the selecting ear 130 from the driving gear 21 and therefiy stopping the forward travel of the sheet.

To accomplish this, the valves 160 and 161 which are interposed between the selecting bellowsl32 and the suction port 39 are controlled by pneumatics 170 and 171, respectively. The pneumatic 170 is connected by conduits 172 and with the duct 61 of the tracker B, while the pneumatic 171 is connected by conduits 173 and 60 with the duct 61 of tracker A. The action of these pneumatics is controlled by the rewind perforations 82 which register with the ducts 61 of the tracker boards. When either of these perforations registers a with the corresponding duct 61, the corresponding valve 160 or 161 islraised, cutting ofi the suction chamber 158 or 159 from the valve chamber 156 or 157 and connecting said chamber with the flushing chamber 57 of the auxiliary wind chest. This action in turn flushes the corresponding suction chamber 143 or 144, allow ing the valve 139 or 140 to drop and connecting the valve chamber 137 01' 138, with the flushing chamber 57, thereby inflating the selecting bellows 132, disconnecting the selecting gear 130 from the driving gear 21 and stopping the sheet.

As before stated, the selecting is done on the idle sheet. Previous to this sheet becoming idle, it wasplayed and the slide valve 38 controlled by the rewind perforation 82 of said sheet was moved into proper position to cause the other sheet to play and the idle sheet to rewind. Therefore the registration of the perforation 82 with the tracker duct 61 to stop the roll when selecting as above described, does notin any way affect the slide valve 38 and the other or playing sheet therefore continues to play.

The primary pneumatics 170 and 171 and 59 and 64 are also connected by auxiliary conduits 174 and 175 with ports .176 and 177 controlled by spring-pressed valves or pallets 178 and 179 which are operated by push buttons 180 and 181, or other suitable means for manually actuating the slide valve 38 to shift the roll-driving mechanism, as previously described. s

For the purpose of manually controlling the cut off 6, a conduit 182 leads to a flushing port 183 in the valve-case or bar 147. This port is controlled by a slide-valve 184 operated by a key or hand lever 185 fulcrumed to the bar 147. Normally, this valve closes said port 183, as shown in the drawings, allowing the cut off valve 6 to assume the position shown and excluding the atmosphere from the box 5. When it is desired to stop the instrument manually for any purpose, the hand valve 185 is opened, allowing the atmosphere to raise the diaphragm 49 and the valve 6, thereby cutting off the main bellows from the wind chests 1 and 52 and flushing the latter,

The operation of the instrument is asfollows:

Assumin the parts to be in position shown in Fig. 2, the tracker A is in playing position and the tracker'B in rewind position, at which time the rewind perforation 82 at the end of the music sheet 11 of tracker A registers with the corresponding tracker- B with the suction port 41 of the valve block 37 collapsing said bellows and moving the rock arm 22 of the driving mechanism of tracker B into playing position, as shown in Fig. 3, and driving the take-up roll.

Simultaneously with the shifting of tracker B into playing position, the driving mechanism of tracker A is shifted into rewind position, as shown in Fig. 3, by said shifting of the slide valve 38. In this position of said valve, the valve chamber 69 is connected with the block-port 41 by the conduits 67 and 79 and port 39, and as the rewind bellows 3 1 of tracker A is connected with said valve chamber 69, it is collapsed and shifts the arm 22 into rewind position, in which it remains until the sheet of the tracker is rewound after which the finger 96 enters the recess 10 1 of the take-up roll and is caused to open the pallet 95. The atmosphere now passes through the conduit 90 and raises the pneumatic stop-valve 87 and rewind valve 69, collapsing the stopping bellows 83 and inflating the rewind ellows 34 of tracker A and shifting the arm 22 into neutral position, thereby stopping the rewinding operation. The arm 22 is held in this position by said stopping bellows 83 as long as the pallet 95 is held open.

The moment the music sheet of tracker B is driven for playing, the tracker board 8 of tracker A is disconnected from the main wind chest by closing of the pouch valves 125 of the suction chamber 112, which latter at this time is flushed through conduits 114 and 66 and open port 40. Thepouchvalves 128 of the other suction chamber 113 are at the same time open, establishing communication between the tracker board of tracker B and the main wind chest.

The music sheet of tracker B continues to play until a rewind perforation '82 thereof registers with the corresponding trackerduct 61 of said tracker. Atmosphere entering the conduit 65 raises the valve '63, collapsing the bellows 51 of the slide val e 37 and shifting the latter into its former positionshown in-Fig. 2. This causes the playing bellows 33 of tracker A to be collapsed, thus again shifting the arm 22into position to drive the take-up roll of tracker A.

Simultaneously with this action, the sheet of tracker B is rewound and stopped in the same manner as above described in connection with the sheet of tracker A. At the same time, the pouch valves 125 of'tra-cker A are opened and the pouch valves 128 of the tracker B arecl'osed,thus silencing the latter, as her'einbefor'e described. N

If, for example, while the music sheet of tracker A is playing and music-sheet of tracker B is r'ewmdmg, it is desirable to manually throw the sheet of tracker B into playing position, the push button 181 is pressed by the operator, thereby opening the masses pallet 178, raising the valve 62, and producingth'e same effect as a perforation 82 at the end of the music sheet of tracker A.

In a similar manner, the driving mechanism of the sheet of tracker A may be thrown into playing positionwhile the sheet of tracker B is playing, by pressing of the push button 180. I

Again, it might be desirable for example to select some particular piece of themusic sheet of tracker B andplace it into playing position while the music sheet of tracker A is playing, in which case the hand lever 153 is set at select. This movement uncovers the port 151 and allows the atmosphere to raise the valve 140, collapsing the selecting bellows 132 of tracker B, engaging the selecting gear 130 with the ear 210i said tracker and driving the ta e up roll forward at increased speed as herinbefor'e described. y 7

As the instrument permits the operator to readily start and stop either of themusic sheets and to select any'desired composition thereon at will, it is especially ado ted for use in moving picture theaters, w are it is desirable to have various kindsofmusic to suit the character of the subjects exhibite It will be noted that the tracker cubofi contains no slides or similar parts liable-to become inoperative by binding and the device is therefore certain and reliable in action.

I claim as my invention:

1 In an instrument otthe character described, the combination of the music and take-up rolls, a rewind shaft, a rewind sienconnected withsaid shaft, a take-up aft having dlfierent siaed rs fixed thank, a driv ng gear, a'ino'vab '0 member on ing main transmission gears arranged to a ternately engage said rewind r and one of the gears of the take-up sha t, said transmission gears being driven by said drivingg'ear, an auxiliary r meshing with the other gear of said ta e upjsh'aftand adapted to move into and out of engagement with said driving gear, and means for shifting said main and auxiliary transmission gears.

2. In an instrumentof the character described, the combination of a tracker, music and take up rolls associated with the tracker, driving mechanism includin members for alternately rotatingf'said r0 lsin o posits directions, auxiliary means for d ri said take-up roll forward at a higher 812% for selecting purposes, and means for automatically t rowing said auxiliary idi'iv' means out ofactlojn tostop the rm, travel of the note sheetbe'fore running 0d the music roll.

3. In an instrument ot'the character described, the combinationof a trackewnmsic and take-up rolls associated with the tracker, driving mechanism including members for alternately rotating said rolls in opposite directions, auxiliary means for drlvin said take-up roll forward at a higher speed or selecting purposes, manual means for throwing said auxiliary driving means into action, and automatic means for throwing said auxiliary driving means out of action to stop the forward travel of the note sheet before running off the music roll.

4. In an instrument of the character described, the combination of a 1plurality of trackers, music and take-up rol s associated with each tracker, driving mechanism includinfi members for alternately rotating the ro s of each tracker in 0p osite directions, auxiliary means for riving said take-up rolls forward at a higher speed for selecting purposes, devices for controlling the action of said auxiliary driving means including actuating pneumatics and valve mechanism controlling the same, manual means for controlling said valve mechanism to throw said auxiliary driving means into action; and automatic controlling means for said valve mechanism including the trackers, to throw said auxiliary driving means out of action.

Witness my hand this 15th day of May,

HENRY COREY DREXELIUS. Witnesses:

C. F. GEYER, E. M. GRAHAM.

(topic: of this patent may be obtained for five cents each, by addressing the Commissioner of ramm,

Washington, D. 0. 

